Today, many users have huge collections of media files such as music and video files stored on a device. The sheer size of the collection can make it difficult for the user to retrieve a media file of interest for him. One solution for solving this problem is to classify those media files according to features characterizing those media files. Assuming that the media file is for example an audio file, then audio files may be characterized with numerous audio features. In the U.S. Pat. No. 7,546,242, it has been proposed to first compute these audio features for each file: for example, one hundred features are computed for each file; then, a graphical element associated to each file and which position depends on these computed features is positioned on a display. As the positions of the graphical elements to be displayed are two or three-dimensional coordinates, it is necessary to reduce the dimensionality from one hundred (corresponding to the one hundred features) to two or three dimensions (corresponding to the two or three dimensions of the coordinates). Therefore, multidimensionality reduction techniques, such as PCA (Principal component analysis), are used. Details about this technique are described in the article “Principal Component Analysis” by S. Wold published in Chemometrics and Intelligent Laboratory Systems, Vol. 2, No. 1. (1987), pp. 37-52. As a result, graphical elements representing the audio files of the audio files collection are positioned on the display in a sparse and discriminative manner. The distance between two displayed graphical elements represents the similarity of the two associated audio files. The user can then easily retrieve an audio file of interest thanks to the meaningful representation of the graphical elements.
When importing a new collection of media files, the position of the graphical elements has to be calculated before being displayed. Once calculated and displayed, the user may retrieve, thanks to the meaningful representation of the graphical elements corresponding to the new imported collection of files, a file of interest. However, the period of time between the import of the new collection of files and the display of the new graphical elements associated to the new imported collection of files may be too long; this prevents the user from retrieving, in a quick and reliable manner, a file of interest belonging to the new imported mass of files.
An object of the invention is to propose a new method achieving this task within a reduced period of time.